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A 10 $\mu$F capacitor is connected to a 210 V, 50 Hz source. The peak current in the circuit is nearly ($\pi = 3.14$):
In a certain region of space, the electric field is along the z-direction throughout. The magnitude of the electric field is, however, not constant but increases uniformly along the positive z-direction, at the rate of $10^5$ NC$^{-1}$ per meter. What is the torque experienced by a system having a total dipole moment equal to $10^{-7}$ C-m in the negative z-direction?
When electron jumps from n = 4 to n = 2 orbit, we get
The ground state energy of hydrogen atom is 13.6 eV. The energy needed to ionise the atom from its second excited state is:
A gramophone record is revolving with an angular velocity $\omega$. A coin is placed at a distance $r$ from the centre of the record. The static coefficient of friction is $\mu$. The coin will revolve with the record if:
Two equal positive charges $Q$ are fixed at points $(a, 0)$ and $(-a, 0)$ on the x-axis. An opposite charge $-q$ at rest is released from a point $(0, y)$ on the y-axis. The charge $-q$ will:
For very high frequencies, the effective impedance of the circuit (shown in the figure) will be:
A body, whose momentum is constant, must have a constant:
A body, under the action of a force $\vec{F} = 6\hat{i} - 8\hat{j} + 10\hat{k}$, acquires an acceleration of $1 \text{ m/s}^2$. The mass of this body must be:
In the figure given below, the position-time graph of a particle of mass 0.1 kg is shown. The impulse at t = 2 sec is:
A body of weight $2 \text{ kg}$ is suspended as shown in the figure. The tension $T_1$ in the horizontal string (in $\text{kg wt}$) is:
A ball of mass 0.25 kg attached to the end of a string of length 1.96 m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved?
A vehicle of mass $m$ is moving on a rough horizontal road with momentum $p$. If the coefficient of friction between the tyres and the road be $\mu$, then the stopping distance is:
A ball of mass 0.1 kg is whirled in a horizontal circle of radius 1 m by means of a string at an initial speed of 10 rpm. Keeping the radius constant, the tension in the string is reduced to one quarter of its initial value. The new speed is:
In a potentiometer arrangement, a cell of emf 1.25 V gives a balance point at 35.0 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63.0 cm, then the emf of the second cell is:
A long solenoid has 1000 turns. When a current of $4 \text{ A}$ flows through it, the magnetic flux linked with each turn of the solenoid is $4 \times 10^{-3} \text{ Wb}$. The self-inductance of the solenoid is:
A block of mass $10 \text{ kg}$ is in contact with the inner wall of a hollow cylindrical drum of radius $1 \text{ m}$. The coefficient of friction between the block and the inner wall of the cylinder is $0.1$. The minimum angular velocity needed for the cylinder, which is vertical and rotating about its axis, will be: ($g=10 \text{ m/s}^2$)
A man is standing on a spring platform. Reading of spring balance is 60 kg-wt. If the man jumps off the platform, then the reading of the spring balance:
An electron enters an electric field with its velocity in the direction of the electric lines of force. Then:
When a torque acting upon a system is zero, then which of the following will be constant?